The test strip disclosed in Patent Literature 1 (Japanese Patent No. 4,264,478), for example, has been disclosed thus far as this type of test strip for biological component measurement. The test strip (biosensor) according to Patent Literature 1 includes a rectangular substrate, a working electrode and a counter electrode that are provided on a top surface of the substrate, separated from each other and extending along a longer direction of the substrate, a reagent portion formed at one end portion of the substrate so as to bridge a gap between the working electrode and the counter electrode, and a spacer and a cover provided on the substrate so as to form a channel from the one end portion of the substrate to the reagent portion. Furthermore, an attribute information output unit that outputs attribute information of the test strip (information for selecting a calibration curve that matches a sensitivity, a measurement item, or the like, for example) is provided on the top surface of the substrate between the working electrode and the counter electrode. At the other end portion of the substrate, the working electrode and the counter electrode each has an electrode terminal for making contact with respective contact points (terminal portions) in a measurement device main body (a concentration measurement device), and the attribute information output unit is provided with a plurality of lead portions for outputting the attribute information.
The attribute information output unit is formed by setting a cutting candidate area and varying a resistance value of the attribute information output unit by cutting the cutting candidate area by machining the area using a drill, laser processing, or etching, for example.
During measurement, a measurement subject's bodily fluid is deposited on the one end portion of the test strip (the substrate), and the other end portion of the substrate (the electrode terminals of the working electrode and the counter electrode) makes contact with the contact points provided in the measurement device main body.
The bodily fluid deposited on the one end portion of the substrate reaches the reagent portion through the flow channel due to the capillary phenomenon, and electrical properties between the working electrode and the counter electrode change due to an electrochemical reaction. The measurement device main body measures a response current value of the reagent portion resulting from a voltage applied thereto via the working electrode and the counter electrode on the substrate, and obtains the attribute information outputted from the attribute information output unit via the plurality of lead portions. The measurement device main body calculates the concentration of a specific component in the bodily fluid based on the response current value and the calibration curve selected based on the attribute information.
Through this, an inaccurate concentration measurement can be prevented even if the sensitivity varies from test strip to test strip.